The present invention relates to a pedal bracket structure for a vehicle brake pedal lever or clutch pedal lever rotatably mounted on the vehicle.
As a pedal bracket structure, various structures have been proposed and in use for a brake pedal lever or clutch pedal lever mounted and rotatably supported on a vehicle such as an automobile. In recent years, pedal bracket structures have been in demand from the viewpoint of crash safety. The pedal bracket structures can effectively prevent the deformation of the pedal toward the driver when impact is applied from front of the vehicle, in particular, in an accident involving a frontal collision. In FIG. 6, a first conventional example of a pedal bracket structure disclosed in Japanese Patent Unexamined Patent Publication No. Hei. 10-297400 is shown, which was proposed as a pedal bracket structure. When an external force that is equal to or greater than a predetermined value is applied from front of the vehicle, the pedal bracket structure can control the displacement of the pedal surface. In this pedal bracket structure, when an external force that is equal to or greater than the predetermined value is applied to the front of the vehicle from front thereof, a certain longitudinal buckling load is inputted into a bracket 110. Side plates 111, 111 of the bracket 110 extend between a bridge member 116 and a mounting member 118. A hole is formed in each of the side plates 111, 111. Consequently, since the longitudinal rigidity of the bracket is decreased by the holes, the bracket is made to crush easily. However, a back plate 140 is provided just above the hole on the side plate 111 to be spaced away from the bridge member 116, whereby the longitudinal rigidity of the bracket is increased. In addition, a flange 142a is disposed on a guide groove bottom surface of the back plate 140. Then, since the flange 142a presses against a pressed portion 131 of a pedal lever 130, the pedal lever 125 swings clockwise, i.e., forward, whereby damage to the driver can be prevented.
In FIG. 7, a second conventional example of a pedal bracket structure disclosed in Japanese Patent Unexamined Publication No. Hei. 9-254821 was proposed as a pedal bracket structure. The pedal bracket structure can ensure that the pedal is withdrawn forward, when energy is inputted to the front of a vehicle. In this pedal bracket structure, a bracket side sliding portion 238 having an inclination angle θ in regard to horizon at an upper end portion of a pedal bracket 222, and a slit 238a is formed in the bracket side sliding portion 238. A vehicle side sliding member 241 is fixed to an instrument panel reinforcement 243. An inclined surface 242 having an inclination angle θ and is formed to be brought into abutment with the bracket side sliding portion 238. A front-end portion of an inclined surface 242 and the slit 238a are fixed with a bolt 240. A direction in which the pedal bracket 222 is released from the bolt 240 is made to substantially coincide with the inclination angle θ of the bracket side sliding portion 238 and the inclined surface 242. Since the bracket side sliding portion 238 released from the bolt 240 is withdrawn along the inclination at the angle θ of the inclined surface 242, a bottom of a pedal lever 218 swings forward of the vehicle accordingly and the withdrawal thereof is restrained.
In the first conventional example of these conventional pedal bracket structures, however, the bracket is constructed so that the longitudinal rigidity is lowered by opening the holes to thereby be easily crushed. Therefore, the back plate 140 is provided on each of the side plate 111 just above the hole to improve the longitudinal rigidity. There may be caused a risk that the deformation promoting function so provided is deteriorated. In addition thereto, since the rigid feeling during the normal pedal operation is reduced, there may be caused a risk that the operability is deteriorated. In the second conventional example, there are involved a number of constituent components, and moreover the large modification is made to the mounting portion to the vehicle body at the rear of the bracket, this making for an increase in production costs.